Bug 127772

Summary: Javascript function returns incorrect value after being JIT-compiled
Product: WebKit Reporter: Daniel Szabo <szdy12>
Component: JavaScriptCoreAssignee: Nobody <webkit-unassigned>
Status: RESOLVED WORKSFORME    
Severity: Major    
Priority: P1    
Version: 528+ (Nightly build)   
Hardware: iPhone / iPad   
OS: iOS 7.0   
Attachments:
Description Flags
html page with javascript showing errorenous JIT behavior none

Description Daniel Szabo 2014-01-28 04:56:09 PST
Created attachment 222429 [details]
html page with javascript showing errorenous JIT behavior

See attachment.
Javascript function 'calc' will be called in a loop.
After several iterations its return value will be zero instead of the reference value.
The non-jitted function 'calc2' (which is the exact copy of 'calc') returns still the reference value.
Actual result on iPad mini (iOS 7.0.4, Safari/9537.53): after 35 iterations the result value will be constant zero.
Comment 1 Daniel Szabo 2014-10-07 02:59:11 PDT
Seems to be fixed in iOS 8 Safari